Add canary upgrade support

[rytswd]

Changed

• Most of setup where it mentioned "no-operator" to use "generated-manifests", which better clarifies the intention
• Documentation links to use absolute path from GitHub repo root

Added

• Canary release support
• Duplicated resource definitions based on installation pattern, such as "as-canary", "before-retiring", "full-installation"
• Created separate directories based on versions for generated manifest setup (Operator will be corrected later)
• New scripts to update definitions for all clusters
• Took out 1.7.8 as a separate setup, and created dedicated scripts and archive directory so that changing the main setup won't cause any change to 1.7.8 release patterns

[rytswd]

Further documentation work will be done separately, as the change is already too large in this PR.